You’ll have to forgive me as we get a little stuck in the weeds. I promise it will be worth it. One of the more interesting debates in statistical circles is in how much fidelity Pythagorean records have. In plain English, can we use run differentials as a way to accurately gauge the quality of a baseball team? It was established baseball “science” for several decades, but science always has a way of updating itself.
For many of you, your eyes have glazed over and you are wondering what this has to
do with the price of whiskey in Ireland. Simply put, Pythagorean records are one of the things we use to determine if a manager is doing a good job and whether teams are overachieving or underachieving. When we spit runs scored and runs allowed into Bill James’ trusty formula, it spits out an expected record based on that differential. The Astros are currently four games better than their expected record. Does this mean Espada is actually doing a good job?
Obviously, that explanation is overly simplistic for a number of reasons. For one, we would have to include the manager’s input into why they have scored and allowed those runs. For instance, do shoddy bullpen decisions lead to more runs allowed? Do you shaky lineup decisions limit runs scored? Is how the manager using players and does that have an impact on player health? These are things that run differentials can’t tell us on their own.
Maybe more importantly to those of us crunching the numbers, we have a baseline explanation for things we have yet to figure out. If we don’t know why something is occurring then we are apt to assume it is random. This is not something we know mind you. It is more of a default that we put in place until a better explanation comes down the pike.
There have been a ton of theories to explain why teams overachieve or underachieve their expected records. Often times, bullpen performance can turn the tide between a good and bad record in one run games for instance. Others point to performance in clutch situations. There certainly is nothing to suggest that those are not factors in Pythagorean records, but most of it comes down to simple math.
There is an affectionate term that I have attributed to the Astros throughout their World Series run. They play something called “bully ball.” Essentially, bully ball occurs when you blow out your opponents. Those games have a way of covering up a ton of sins. Suddenly, numbers like performance with runners in scoring position or with two outs suddenly look a lot better. However, the difference between a 7-2 win and an 11-2 win are negligible for those of us watching the game.
Before we look at the obligatory table, one must appreciate the history of all this. Teams that win 100 or more games almost always overachieve their Pythagorean record. In other words, there is some luck involved in piling on that many wins. I want you to notice what happens to the Astros win differentials in those seasons where they won 100 or more games (2017, 2018, 2019, 2022).
Based on the Pythagorean records, the Astros should have won 100 or more games in 2021 as well. So, they not only won 100 or more games four times, but they SHOULD have won 100 or more games four times. That is extremely rare and when you remove 2020, those seasons would have happened consecutively. I think we need to take a step back and appreciate how unique that is. There aren’t many teams in history that can say the same thing. You can probably count them on one hand.
if you remove 2026 from the equation, the Astros record in blowout games (games decided by four or more runs) moves to 259-123. That is a .678 winning percentage. That is absolutely stupid good. That would be equivalent to 110-52 in a 162 game schedule. You’ll notice that the Pythag differentials started to change in 2025 when the Astros weren’t quite as good at blowing out opponents. This year has been an inverse of their recent history dating back to 2017.
If you’ve gotten this far then you’ve reached the point where we can arrive at some conclusions. First, this is not a good baseball team. I know I’m not breaking any ground there and I know many of you are thinking you don’t need the fancy numbers to tell you that. However, the Pythagorean records say they shouldn’t even be .500 and we should take a step back before we reach that conclusion because this team gets its doors blown off with more frequency than in the past.
The second point is that it is fair to suggest that Espada is doing a good job based on these numbers alone. One could argue that the art of giving up on a lost game helps preserve players for future games when they are close. I’m not sure I would completely buy into it, but it an understandable inference from the numbers above. I do think it is important to look at the differences in how these numbers break down. By sheer definition, you would likely have to score five runs or more to register a blowout. The Astros did so 23 to 37 times between 2017 and 2025 and registered between 28 and 37 between 2017 and 2024. They have only 13 with approximately 30 games to go. Unless they suddenly go absolutely nuts down the stretch, they will drastically underachieve in that department.
Many will point to the Astros;’ pitching woes as a reason for the decline in this department and it certainly is a factor, but the offensive challenges have also played a dramatic role. This means that independent of what happens to Espada, this team was not good enough when constructed. Certainly, the use of certain players will come into focus when management makes the call on Espada. The end result is that Pythagorean records are one tool we can use to evaluate managers, but they shouldn’t be the first tool and obviously should not be the only tool.
